The body structure of a motor vehicle should be designed in such a way that dynamic rigidity requirements (for example requirements on torsional rigidity when driving through a curve about a central longitudinal axis of a vehicle) are fulfilled. In addition, the vehicle body structure should also be designed in such a way that in the case of a crash, the impact forces can be directed into the body structure of the vehicle for the most part without deformation.
DE 10 2006 013 550 A1 discloses a vehicle of the generic type which is provided with an auxiliary front frame used as a chassis suspension which is connected to the lateral longitudinal braces of the vehicle body. The vehicle is in addition also provided with a tunnel transverse carrier that serves as a drive assembly-bearing component. This component is arranged at an offset form the auxiliary frame in the longitudinal direction of the vehicle and it bridges over a central tunnel on the side of the vehicle body in the transverse direction of the vehicle. The auxiliary frame and the tunnel cross-member form together a supporting base on which a drive assembly of the motor vehicle can be supported via the bearing points, for example with a three-point bearing construction.
In a front carriage described in DE 10 2006 013 550 A, the vehicle body suspension (that is to say the auxiliary frame) and the assembly-bearing component (that is to say the tunnel transverse member) are arranged at a distance from each other, in particular so that they are connected to each other without transmitting force. This generally results in a split arrangement of the auxiliary frame and of the other supporting structures reinforcing the vehicle body. This split arrangement thus can fulfill the requirements on the rigidity of the vehicle body only to a reduced extent.
From DE 11 2008 307 T5 is known another motor vehicle in which the tunnel transverse member is connected via a strut arrangement in a power-transmitting manner to the front vehicle body longitudinal carriers. In the event of a crash, an additional load path is formed, which bifurcates at the connection point between the longitudinal carriers of the vehicle body and the strut arrangement and then continues via the tunnel transverse carrier to the longitudinal carriers.
The object of the invention is therefore to provide a motor vehicle wherein the rigidity requirements mentioned above can be fulfilled in a simple manner.